1. Field of the Invention
The present invention relates to the field of telecommunications. More particularly, the present invention relates to optimizing the design of trunk routing among switches in a telecommunications network.
2. Acronyms
The written description provided herein contains acronyms which refer to various telecommunications services, components and techniques, as well as features relating to the present invention. Although some of these acronyms are known, use of these acronyms is not strictly standardized in the art. For purposes of the written description herein, the acronyms are defined as follows:
Answer Complete Message (ACM)
Answer Message (ANM)
Call Detail Record (CDR)
Centum-Call Seconds (CCS)
Central Exchange Service (Centrex)
Carrier Identification Code (CIC)
Competitive Local Exchange Carrier (CLEC)
Data Collection Operations System (DCOS)
Electronic Key Telephone System (EKTS)
Generic Access Profile (GAP)
Grade of Service (GOS)
Graphical User Interface (GUI)
HyperText Mark-Up Language (HTML)
HyperText Transfer Language Protocol (HTTP)
Incumbent Local Exchange Carrier (ILEC)
Initial Address Message (IAM)
Interexchange Carrier (IXC)
Internet Service Provider (ISP)
Local Exchange (NXX)
Local Routing Number (LRN)
Numbering Plan Area (NPA)
Plain Old Telephone Service (POTS)
Private Branch Exchange (PBX)
Public Switched Telephone Network (PSTN)
Release (REL)
Release Complete (RLC)
Secure Sockets Layer (SSL)
Service Control Point (SCP)
Service Switching Point (SSP)
Signaling System 7 (SS7)
Signaling Transfer Point (STP)
Transaction Capabilities Application Part (TCAP)
Transmission Control Protocol/Internet Protocol (TCP/IP)
Trunk Circuit Identification Code (TCIC)
Trunk Integrated Records Keeping System (TIRKS)
Total Network Data System (TNDS)
3. Background Information
The public switched telephone network (PSTN) consists generally of a series of switches capable of logically routing calls through the telecommunications network based, in part, on call origin and destination. Commonly, the PSTN includes two types of switches: class five switches, also known as an end office or a service switching point (SSP), and class four switches, also known as a tandem switch. The switches are controlled by associated signaling transfer points (STPs) and service control points (SCPs), which provide instruction on call routing, as well as a variety of network implemented call services.
The end offices connect the PSTN to the network users' telephone systems, including business related Centrex and private branch exchange (PBX) systems, as well as the plain old telephone service (POTS) systems, relied on by most residential customers. Other users involve entire networks, such as Internet service providers (ISP) and the like. The tandem switches are intermediate switches, incorporated in routing between the originating end office and the terminating end office. The various switches in the PSTN are connected by communication lines called trunks. A group of similar trunks that connect the same geographic locations are referred to as trunk groups. Depending on the volume of traffic, several trunk groups may simultaneously service two particular points in the PSTN.
The trunk groups interconnecting the switches are designed and implemented based on analysis of telecommunications traffic, which has consistently and dramatically increased over the past several years. Trunk planners and network design engineers attempt to identify communications paths among switches that carry an especially high amount of traffic or load from point to point. Switches carrying especially high loads are connected with direct trunk groups to accommodate the traffic, preferably without wasting resources. As PSTN traffic increases, along with the number of interconnecting carriers, such as competitive local exchange carriers (CLECs), wireless carriers, interexchange carriers (IXCs) and independent carriers, the new and shifting traffic depend largely on tandem switches as primary hubs. The increased traffic loads and carriers have exhausted the tandem switches driving increased capital investment in the PSTN (e.g., additional tandem switches and associated trunk groups). Often, though, tandem switches and trunk groups are added to relieve overburdened resources, while other existing tandem switches and trunk groups are not being used to their fullest capacity. This misuse of resources is due to the limited ability to accurately quantify and analyze the actual traffic loads at each tandem switch.
The dynamic nature of network traffic enables continual production of new and different “communities of interest” between end offices, which create opportunities to off-load traffic from the exhausted tandem switches. There are various types of communities of interest, the respective identities of which depend on purpose and location. For example, ISP traffic is a community of interest based on a centralized ISP location, which ordinarily exists outside a major metropolitan area. In contrast, a business related community of interest, involving a Centrex system, for example, would likely be centered in a metropolitan area, requiring an entirely different routing scheme.
Under the existing methodology, however, opportunities to off-load traffic are difficult, if not impossible, to identify. For example, in the past, network designers have analyzed traffic loads on a switch by switch basis, looking at the inbound and the outbound loads at an end office, only, and primarily relying on manual quantification of the required trunk groups between any two end points. The quantification data was largely anecdotal (e.g., statistical and empirical sampling), as opposed to empirically comprehensive. The designers were not able to precisely correlate a set of intervening tandem switches that enabled the line of communication for two end points (e.g., a point to point community of interest). Also, the designers were not able to effectively implement information that was potentially available to them. Therefore, it was difficult to identify and size new high usage groups within the PSTN, leaving the bulk of the communications traffic on the tandem switches.
The present invention overcomes the problems associated with the prior art, as described below.